Answer:
It is produced in the receptors of the axon and it travels trough the synaptic vesicles on the motor end plate.
Step-by-step explanation:
Acetylcholine is produced by a series of enzymatic reaction in the neuron terminal, it is stored in small sacs called vesicles until an electrical impulse arrived and release them in the space among neurons called synapse.
When this neurotransmisor reaches another neuron, it is bonded in the acetylcholine receptors. The effect of this chemical substance is to contract the muscles like the heart muscles, by opening the sodium - potassium channel on it.
Hope this info is useful.